CA2544439A1 - Tube for medical fluid passage switching apparatus - Google Patents
Tube for medical fluid passage switching apparatus Download PDFInfo
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- CA2544439A1 CA2544439A1 CA002544439A CA2544439A CA2544439A1 CA 2544439 A1 CA2544439 A1 CA 2544439A1 CA 002544439 A CA002544439 A CA 002544439A CA 2544439 A CA2544439 A CA 2544439A CA 2544439 A1 CA2544439 A1 CA 2544439A1
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- tube
- cam
- fluid passage
- passage switching
- closing
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Abstract
Disclosed is a tube for use in a medical fluid passage switching apparatus for carrying out a series of fluid passage switching actions of a plurality of tubes connected to each other at one end. The tube is decreased in diameter and/or thinned in a wall at a region where a cam of the apparatus or a combination of the cam and a clamp of the apparatus is engaged with the tube by closing and opening the tube as compared with a region where the tube is not engaged with the cam or the combination of the cam and the clamp. The tube allows for minimization of the overall size and reduction in the number of components of the apparatus while maintaining the desired fluid flow.
Furthermore, the tube minimizes the strength required for actuating the cam to close the tube and minimizes damage to the tube.
Furthermore, the tube minimizes the strength required for actuating the cam to close the tube and minimizes damage to the tube.
Description
TUBE FOR MEDICAL FLUID PASSAGE SWITCHING APPARATUS
This is a divisional application of Canadian Patent Application No. 2,341,194 filed on October 19, 1998.
Field of the Invention The first invention relates to a medical fluid passage switching apparatus and particularly, to a fluid passage switching apparatus mounted to a Y-shaped connecting tube in a CAPD (continuous ambulatory peritoneal dialysis) system as shown in Fig. 4.
The second invention relates to a component of the medical fluid passage switching apparatus of the first invention and particularly, to a tube employed in the apparatus.
An embodiment of the present invention relates to a CAPD system employing the medical fluid passage switching apparatus.
Claimed in this divisional application is a tube for use in a medical fluid passage switching apparatus for carrying out a series of fluid passage switching actions of a plurality of tubes connected to each other at one end. It should be understood that the expression "present invention"
in this specification encompasses the subject matter claimed both in this divisional and the parent applications.
Prior Art (1) In a conventional back-free, twin-bag system of the CAPD technology, it is necessary to operate three clamps K1, K2, and K3 in a specific order shown in Table 1, wherein the clamp K1 is mounted to a first tube 1 connected at one end to a catheter implanted in the body of a patient, the clamp K2 is mounted to a second tube 2 connected at one end to a Y-shaped joint 4 joined to the other end of the first tube 1 and at the other end to a dialysis liquid bag 5 for supplying a fresh charge of a dialysis liquid to the patient, and clamp K3 is mounted to a third tube 3 connected at one 1a end to a drain bag 6 for collecting and discarding the charge of the dialysis liquid stored in a peritoneal cavity of the patient for a given period of time.
Table 1:
Initial State K1 closed K2 opened K3 closed Discharge K1 opened K2 closed K3 opened Flushing K1 closed K2 opened K3 opened Charge K1 opened K2 opened K3 closed End of Steps K1 closed K2 closed K3 closed In the table, the number of steps is denoted by the symbols arrow For completing a sequence of the steps, the patient is requested to carry out eight actions for opening and closing the clamps. Those actions are troublesome and may lead to mistakes. Also, this will discourage the application of the conventional system to a new, unskilled patient. For solving the above problems, a novel technique is developed and disclosed in the PCT unexamined Japanese Publication (Tokko-Hei) 2-502882.
This is a divisional application of Canadian Patent Application No. 2,341,194 filed on October 19, 1998.
Field of the Invention The first invention relates to a medical fluid passage switching apparatus and particularly, to a fluid passage switching apparatus mounted to a Y-shaped connecting tube in a CAPD (continuous ambulatory peritoneal dialysis) system as shown in Fig. 4.
The second invention relates to a component of the medical fluid passage switching apparatus of the first invention and particularly, to a tube employed in the apparatus.
An embodiment of the present invention relates to a CAPD system employing the medical fluid passage switching apparatus.
Claimed in this divisional application is a tube for use in a medical fluid passage switching apparatus for carrying out a series of fluid passage switching actions of a plurality of tubes connected to each other at one end. It should be understood that the expression "present invention"
in this specification encompasses the subject matter claimed both in this divisional and the parent applications.
Prior Art (1) In a conventional back-free, twin-bag system of the CAPD technology, it is necessary to operate three clamps K1, K2, and K3 in a specific order shown in Table 1, wherein the clamp K1 is mounted to a first tube 1 connected at one end to a catheter implanted in the body of a patient, the clamp K2 is mounted to a second tube 2 connected at one end to a Y-shaped joint 4 joined to the other end of the first tube 1 and at the other end to a dialysis liquid bag 5 for supplying a fresh charge of a dialysis liquid to the patient, and clamp K3 is mounted to a third tube 3 connected at one 1a end to a drain bag 6 for collecting and discarding the charge of the dialysis liquid stored in a peritoneal cavity of the patient for a given period of time.
Table 1:
Initial State K1 closed K2 opened K3 closed Discharge K1 opened K2 closed K3 opened Flushing K1 closed K2 opened K3 opened Charge K1 opened K2 opened K3 closed End of Steps K1 closed K2 closed K3 closed In the table, the number of steps is denoted by the symbols arrow For completing a sequence of the steps, the patient is requested to carry out eight actions for opening and closing the clamps. Those actions are troublesome and may lead to mistakes. Also, this will discourage the application of the conventional system to a new, unskilled patient. For solving the above problems, a novel technique is developed and disclosed in the PCT unexamined Japanese Publication (Tokko-Hei) 2-502882.
(2) The technique disclosed in the PCT unexamined Japanese Publication (Tokko-Hei) 2-502882 has an actuator of substantially a cylindrical shape installed in substantially a tubular housing and is connected to a valve having three ports which are in turn communicated to a first, a second, and a third tube. The valve is actuated between four positions: a position for shutting off all the ports, a position for ensuring a passage laid-open for fluid between the first and second ports, a position for ensuring a passage laid-open for fluid between the second and third ports, and a position for ensuring a passage laid-open for fluid between the first and third ports.
However, such an arrangement requires extra means for ensuring the air-tightness and liquid-tightness in both the actuator and the housing. If the air-tightness and liquid-tightness is imperfect, bacteria existing in the air may enter the peritoneal cavity hence causing peritonitis.
According to the previous invention, the actuator and the cylindrical housing are sealed for having a quality of air-tightness and liquid-tightness with the use of 0-rings which are still unsatisfactory.
Disclosure of the Invention The present invention provides a fluid passage switching apparatus in a medical system and particularly a fluid passage switching apparatus in a CAPD (continuous ambulatory peritoneal dialysis) system, which comprises: a rotatable shaft; a cam which is rotated in relation to the rotating movement of the shaft to close and open each tube for determining passages of fluids; and a housing which is so arranged to hold the cam, and has holes for accommodating the tubes therein, wherein each tube communicating one another, and the cam comprises a member for closing and opening each tube for determining passages of the fluids, whereby a series of fluid passage switching actions can be carried out easily.
With such a fluid passage switching apparatus in a CAPD
(continuous ambulatory peritoneal dialysis) system, a series of fluid passage switching actions can easily be carried out without producing leakage of the fluid and suffering from microbism.
The present invention also provides such a fluid passage switching apparatus having an improved fitting structure of the housing, where the housing is assembled at high accuracy to have precise dimensions but with much ease and can hardly be disassembled pieces after assembled hence giving a good enough level of safety.
An aspect of the present invention provides a tube capable of minimizing the overall dimensions of the fluid passage switching apparatuses of the first and second objects.
The fluid passage switching apparatus of the present invention is improved in installing a plurality of clamps which are commonly used, are small in size, and assembled without much difficulty for clamping the tubes, thus avoiding any assembling fault such as absence of any clamp.
3a Brief Description of the Drawings Fig. 1 is a schematic view showing a back-free, twin-bag system in a conventional CAPD method;
Figs. 2 and 3 illustrate an embodiment of a fluid passage switching apparatus according to the present invention;
Fig. 4 is a schematic view showing a back-free, twin-bag system in a CAPD method employing the fluid passage switching apparatus of the present invention;
Fig. 5 illustrates a notched structure of a cam used in the fluid passage switching apparatus of the present invention; _ .
Fig. 6 is a diagram of a first positioning action of clamps selectively carried out in the fluid passage switching apparatus of the present invention for closing and opening, showing an initial state at (I), a discharge preparation state at (2), and a discharge state at (3); ., Fig. 7 is' a diagram of another positioning action of the clamps selectively carried out in the fluid passage switching apparatus of the present invention for closing and opening, showing a flushing preparation state at (4); a flushing state at ~(5), and a charge preparation state at (6);
Fig. 8 is a diagram of a further positioning action of the clamps selectively carried out in the fluid passage switching apparatus of the present invention for closing and opening, showing a charge state at (7), and an end-of action state at ($);
Fig. 9 is a diagram of the first positioning action with a tube K1 controlled fox closing and opening by a patient while other tubes K2 and K3 r 3b controlled with a plane cam, showing the initial state at 1~, the discharge preparation state at 0, and the discharge state at ~;
Fig. 10 is a diagram of the another positioning action with the tube Kl controlled for closing and opening by a patient while the other tubes K2 and controlled with the plane cam, showing the flushing preparation state at ~, the flushing state at 5~, and the charge preparation state at ~;
Fig. 11 is a diagram of the further positioning action with the tube K1 controlled for closing and opening by a patient while the other tubes K2 and controlled with the plane cam, showing the charge state at ~, and the end-of action state at ~;
Fig. 12 is a view of shells to be assembled to a fitting structure of a housing, showing an upper shell provided with a notch at (a) and a lower shell having a rib and a latch at (b); and Fig. 13 is a view of the shells shown in Fig. 12 assembled together, showing the fitting structure.
Embodiments of the Invention Fig. 2 illustrates a fluid passage switching apparatus comprising a shaft F provided with an operating handle A for pivotably holding a cam C, an upper housing shell D of a cylindrical shape having a through hole G for the shaft F and a tube accepting aperture H provided therein and arranged to fit with a lower housing shell E to form a housing for accommodating the cam, the lower housing shell E of a cylindrical shape having a tube accepting aperture I
therein at a location which is opposite to the tube accepting aperture H of the upper housing shell D, and the cam C accommodated in the housing consisting of the upper housing shell D and the lower housing shell E and arranged to be rotated by the movement of the handle A to its selected positions for opening and closing a tube B.
Fig. 3 shows another fluid passage switching apparatus having a cam C
and an operating handle J which is formed integral with a shaft joined rotatably to the cam C held to a housing L.
Also, the present invention includes a further fluid passage switching apparatus having a member provided in a housing thereof for transmitting a force to a tube of a cam to shut up the tube. The member for transmitting a force to the tube to shut up the tube may be a clamp which is movable in response to a rotating movement of the cam for closing and opening the tube.
With such a fluid passage switching apparatus mounted to a Y-shaped tube joint, e.g., of a CAPD (continuous ambulatory peritoneal dialysis) system, the switching is made at particular positions listed in Table 2. The opening and closing actions of the clamp when the positions listed in Table 2 are selected in the flow passage switching apparatus of the present invention are illustrated in Figs. 6 to 8. As shown in Figs. 6 to 8, the tubes are open when notches of the cam come across and otherwise, they are closed. The notches are provided at intervals of 90 degrees and when moved to 45 degrees, come to their next positions.
Table 2:
X position 1 K1 K2 K3 I
(initial state) open open open position 2 (prepareKl K2 K3 for dischar e) closed closed closed position 3 Kl K2 K3 (dischar e) open closed open position 4 (prepareKl K2 K3 for flushin ) closed closed closed position 5 Kl K2 K3 (flushin ) closed o en o en position 6 (prepareKl K2 K3 ~ closed ~ closed for char e) closed position 7 Kl K2 K3 (char e) o en open closed position 8 Kl K2 K3 (end of action) closed closed closed necessary positions, X : position required for the production, ~: preferably adopted position, O: preferably adopted positions in the prior art but unnecessary positions in the present invention.
The positions listed in Table 2 will now be explained in more detail.
At the initial state, the clamps Kl, K2, and K3 in the fluid passage switching apparatus when released from its package remain opened for preventing blocking up of the tubes during sterilization.
The selection from the positions listed in Table 2 may be made by manually turning the shaft or by full- or semi-automatic control of a relevant mechanism where the positions 4 to 6 are automatically controlled by time setting while the positions 1 to 3 and 6 to 8 are manually determined depending on the personal conditions of a patient such as discharge speed.
In the prior art, it is necessary to execute simultaneous actions of opening and closing the clamps Kl, K2, and K3 for determining their positions listed in both Tables 1 and 2. The present invention permits the cam to systematically control a desired group of the clamps without manually operating all the clamps. For example, in the apparatus with the cam controlling all the clamps Kl, K2, and K3, the position can be selected by using the handle while no action of manually opening and closing the clamps Kl, K2, and K3 is needed.
Accordingly, the switching of the fluid passage can easily be carried out by a patient. Also, as the fluid passage is switched by the cam or clamps pressing down and releasing the tubes, leakage of the fluid or entry of undesired bacteria can be avoided.
The present invention is not limited to the apparatus with the cam controlling all the clamps Kl, K2, and K3 and another type shown in Figs. 9 to 11 may be implemented with a cam controlling the clamps K2 and K3 while the clamp K1 is operated by a patient.
Illustrated in Figs. 9 to 10 are the action of the plane cam in response to the movement of a shaft for closing and opening the tubes at its positions.
Denoted by ~ is the initial position, 2Ois the preparatory position for discharge, ~ is the discharge position, ~ is the preparatory position for flushing, ~5 is the flushing position, ~is the preparatory position for charge, O7 is the charge position, and ~ is the end of action.
The opening and closing states of charge and discharge tubes are listed in Table 3. In Table 3, O represents the opening state of the tube and X
represents the closing state.
Table 3:
Positions ~ ~ ~ ~ ~ ~ ~
Charge tube O X X X O X O x Discharge O X O X O X X X
tube In this embodiment, the two clamps located on the same plane are controlled with a single plane cam. It is also possible to have two or more clamps arranged in parallel and controlled with the use of a corresponding number of plane cams aligned along the same shaft 90 degrees out of phase to one another.
The components of the fluid passage switching apparatus in a medical system according to the present invention will be described in more detail.
(1) Housing ~l As shown in Fig. 2, the housing comprises an upper shell D and a G
lower shell E. The upper shell D and the lower. shell E define a room in which a cam C and clamps are accommodated. The upper shell D has a handle through hole and markings of the positions for switching the flow passage provided in and on the top side thereof. The markings include the positions 3 to 8.
Tube apertures across which the tubes to be opened and closed by the cam or the clamps extend are provided in the sides of the upper and lower shells.
~2 The housing is preferably shaped to a cylindrical form and sized as small as possible.
The housing may be made of metallic material such as stainless steel etc. , ceramic, or heat-resistant synthetic resin such as polyacetal, polycarbonate, polypropylene, ABS resin, or polyethylene.
It is unnecessary to accommodate the cam in the housing. The housing is not limited to the shape and the construction so long as it can securely hold the shaft, the cam joined to the shaft, and the clamps as shown in Fig. 3.
~3 For ensuring the closing of the tube with the cam or a combination of the cam and the clamp while providing the operability of the cam with the handle, it is essential to assemble the upper shell D and the lower shell E to highly accurate dimensions. Particularly, ensuring the closing of the tube is most important and hence, the dimensional accuracy of the upper shell D and the lower shell E along the vertical direction (the thickness direction) will be crucial and towards the upward direction (a direction along which the upper shell D is separated from the lower shell E) will be more crucial. The dimensional accuracy shall be affected by any faint injury produced at the joint during the assembling of the housing by joining the two shells to each other along the vertical direction.
For eliminating the above drawback, we, the inventors, joined the upper shell D and the shell E by adhesive to each other to develop a test piece and failed to have a desired level of the dimensional accuracy A desired level of the dimensional accuracy was achieve when the two shells were assembled by thread joining which however required a considerable length of ~dorking time.
Accordingly, it was found that the thread joining was not an appropriate method in the view of practical production.
Through a series of experiments, we, the inventors, found that the upper shell D and the lower shell E were joined to each other for achieving the above task not by the thread joining but by giving a specific fitting arrangement which is described below in more detail.
The fitting arrangement is implemented by placing the upper shell D
over the lower shell E, turning it to engage its notch P with a rib Q provided on the lower shell E, and sliding and fitting a latch R of the lower shell E to a predetermined location in the notch P, as shown in Figs. 12a and 12b. In the fitting arrangement, the engagement between the notch P of the upper shell D
and the rib ~.l of the lower shell E determines the vertical position of the two shells D and E. When the latch R has been moved over a slope U provided on the upper shell D, its side r1 comes opposite to a facet p1 of the notch P in the engagement.
The use of the fitting arrangement permits the notch P and the rib Q for determining the vertical positioning of the housing to be free from physical injury during the joining, hence achieving a desired level of the dimensional accuracy on the housing. Also, the latch R of the lower shell E, the slope U
and the facet p1 at the notch P of the upper shell D may be injured due to severe friction. Such resultant injuries are too small to affect on the vertical dimensional accuracy of the housing.
The latch R makes the engagement between the upper and lower shells D
and E easy and after the engagement, acts as a stopper which prevents the separation of the two shells from each other. Accordingly, the latch R is not limited to a particular shape while providing the above mentioned function.
Preferably, the latch R has a facet r2 provided thereon for ease of the assembling the upper and lower shells. The rib Q and the latch R may be formed integral with the lower shell E or fabricated separately and then joined to the lower shell by an appropriate joining means.
The shape of the rib Q in the fitting arrangement is not of limitations while it enables to engage with the notch P for determining the vertical positioning of the upper and lower shells. Preferably for improving the strength of the apparatus, the location of the rib Q and the notch P is so determined that the edge region at the open end of the lower shell where the rib Q is provided comes into direct contact with the inner side of a circular top region of the upper shell.
The fitting arrangement is not limited to that shown in Figs. 12 and 13 and an alternative rnay be used where the notch P is provided in the lower shell E while the rib Q and the latch R are provided on the upper shell D.
Also, the fitting arrangement may include a means for determining the vertical positioning (particularly along the upward direction) so as to allow any two horizontally extending surfaces to directly fit each other. Although the downward positioning is determined by the facet q1 of the rib Q and the facet p2 at the notch P and the upward positioning is by the facet q2 and the facet p3 in the above example, they may be determined by the facet r3 of the latch R
and the facet p2 at the notch P and by the facet q2 and the facet p3 respectively so that facet r1 of the latch R and the facet p1 at the notch P come into direct contact and are engaged with each other. Furthermore, it is possible that the dimensional accuracy along the upward direction at least is maintained by the facet q2 of the rib Q and the facet p3 at the notch P with a clearance provided between the facet q1 and the facet p2 at the notch P so that the facet r1 of the latch R and the facet p1 at the notch P directly engage with each other.
Although at least a single of the fitting arrangement is sufficient to be provided in the housing, it is preferred to have two to five of the fitting arrangements to prevent leftward and rightward displacement of the upper shell D and the lower shell E during the turning movement of the shaft.
(2) Shaft The apparatus allows the patient or operator to select desired one of the positions by turning the handle joined to the shaft.
(3) Cam The cam has a construction which is rotated by the controlling action of the shaft to any desired position for opening or closing the corresponding tube directly or with the help of a clamp and may be selected from a plane cam and a solid cam.
The cam employed in the embodiment has notches provided therein as shown in Figs. 2 and 5. The structure a of the cam shown in Fig. 5 includes a portion b for maintaining the tube at its opening state, a portion c for shifting the tube from the closing state to the opening state, a portion d for maintaining the tube at its closing state, and a portion a for shifting the tube from the opening state to the closing state.
The distance between the portion b for maintaining the tube at its opening state and the portion d for maintaining the tube at its closing state is a length required for opening or closing the tube with or without the clamp. For example, in case that the tube is closed with the cam and its thickness is ignored, the distance is substantially identical to the diameter of the tube.
When the cam is involved, its shape varies the distance which shall be higher or lower than the diameter of the tube.
The portion c for shifting the tube from its closing state to the opening state is diverted an angle of 45 to 135 degrees clockwisely from the horizontal plane of the portion d and preferably, within a range from 85 to 95 degrees to prevent the reverse rotation. The angle of the portion a for shifting the tube from the opening state to the closing state is determined by the angle of the clamp. Because the strength is not required at the initial stage of closing the tube but needed at the final stage for pressing down the tube, it is preferable that the portion a consists of a steep slope III and a moderate slope II as shown in Fig. 3. The moderate slope II which transmits the pressing force of the cam continuously and lightly to the distal end IV of the clamp may preferably have a curved surface rather than a flat surface.
The cam C has a circular shape in the plan view of which the diameter is 40 to 90 percent of the diameter of the housing comprising the upper shell D
and the lower shell E and more preferably 70 to 80 percent.
The number of the notches shown in Fig. 4 and 5 is determined by the number of the positions.
When the positions are three, one notch is provided. The positions for discharge, flashing, and charge are essential as their tasks are satisfied with K2 closed, Kl closed, and K3 closed respectively. As shown in Fig. 5, one single notch d does the tasks. If four to eight of the positions are desired, the number of the notches is 3.
(4) Tube Ol The tube commonly employed in a medical fluid passage switching apparatus (e.g. for a CAPD passage) may be of 5 mm in the inner diameter and 7 mm in the outer diameter. However, when the tube of such a size is used in the medical fluid passage switching apparatus which comprises at least a rotatable shaft, a cam arranged for turning in relation to the rotating movement of the shaft to open and close the tube which provides a fluid passage, and a housing having tube holes provided therein and arranged for accommodating the cam, the overall size of the apparatus will be increased.
The reason is that the diameter and the height of the cam are determined by the outer diameter of the tube while the height of the interior space of the housing should be greater than the outer diameter of the tube. Also, as the tube is made greater in the outer diameter and the thickness, the force l0 requireel on the handle has to be increased thus disturbing the rotating operability of the handle.
~J When the tube employed in a nnedical fluid passage switching apparatus (e.g. for a CAPD passage) is decreased in the size, the drawback that the overall dimensions of the apparatus becomes large may be eliminated. On the other hand, the reduction of the tube size, particularly the inner) diameter, will decrease the flow of a fluid. For example, with a tube having 3 mm of the inner diameter instead of 5 rrim in the inner diameter and 7 mm in the outer diameter, the discharge took 5 % more in duration than with the above mentioned tube.
According to the present invention, the size, particularly the firmer diameter, of the tube shall be determined in consideration with the duration required for the discharge caused by the reduction of diameter of the tube.
The tube having a reduced diameter may be 1 to 4 rr>ln in the inner diameter and 2 to 5 mm in the outer diameter. It is more preferable that the inner diameter is 3.5 mm, the outer diameter is 4.5 mm, and the thickness is 0.5 mrn.
The diameter reduction of the tube may be implemented at each particular portion on which the clamp or a combination of the clamp and the cam presses down to open and close the tube., Alternatively, the entire body (of a three-directional shape) of the tlxbe in the apparatus may be reduced in the diameter.
The three-directional tube may be arranged so that gradually increasing its diauneter 1T'Om their opeming/closing portion towards the open end of each directional tube.
For example, the open end of each branch of the three-directional tube is sized to 2 ix~ 9 mm in the inner diameter and ~l to 10 nm in. the outer diaxmeter for ease of joining with conventional tubes.
'rhe i;hree-directional tube may be fabricated by bonding the portions of reduced diameter with other portions by adhesive or be unified by injection molding.
Also, the portions other than the portions of reduced diameter may preferably be fabricated by rW g-life members which can sandwich holes H of the upper shell D
and holes.I of lower shell E fram both outer and inner sides of housing or a member having ring-like region to be provided on the outer side of holes I-i of the upper shc, )l D. The ring-like members or regions permit; the three-directional tube to be easily secured to t;he housing. The ring-like regions may be shaped by integral rnoldini; or the ring-like members may be joined to the tube by appropriate joining means.
The thickness of the tube is a critical factor for determining the strength required for ensuring the air-tightness in the tube. The smaller the thickness, the less the strength is required for ensuring the air-tightness in the tube thus improving the rotational operability of the shaft. The thickness may be 0.1 to 1.5 mm and more preferably, 0.3 to 0.7 mm.
When the thickness of the tube to be closed and opened is as small as 0.3 to 0.7 mm, the apparatus will be of a (direct) type where the tube can directly be closed with the cam.
~3 It was found through , studying the reduction of the number of components and the dimensions of the medical fluid passage switching apparatus and the decrease of the height of the apparatus that while a commonly adapted tube having 5 mm of an inner diameter and 7 mm of an outer diameter suffered from damage when pressed down directly with the cam for closing and opening, the tube having a thickness of 0.3 to 0.7 mm was successfully pressed down for closing and opening by the cam without being damaged.
It is presumed that the reduction of the thickness of the tube minimizes the strength required for actuating the cam to close the tube.
In such a direct type of the apparatus, the clamp can be omitted and thus the thickness of the cam can be decreased . Accordingly, in addition with the effect of the tube having a reduced thickness of tube wall and reduced inner diameter, the medical fluid passage switching apparatus can be minimized in the number of its components, reduced in the height, and designed to a compact structure. Also, as the direct type of the apparatus is shortened along the radial direction as well as in the thickness direction, its overall dimensions can further be reduced.
However, such an arrangement requires extra means for ensuring the air-tightness and liquid-tightness in both the actuator and the housing. If the air-tightness and liquid-tightness is imperfect, bacteria existing in the air may enter the peritoneal cavity hence causing peritonitis.
According to the previous invention, the actuator and the cylindrical housing are sealed for having a quality of air-tightness and liquid-tightness with the use of 0-rings which are still unsatisfactory.
Disclosure of the Invention The present invention provides a fluid passage switching apparatus in a medical system and particularly a fluid passage switching apparatus in a CAPD (continuous ambulatory peritoneal dialysis) system, which comprises: a rotatable shaft; a cam which is rotated in relation to the rotating movement of the shaft to close and open each tube for determining passages of fluids; and a housing which is so arranged to hold the cam, and has holes for accommodating the tubes therein, wherein each tube communicating one another, and the cam comprises a member for closing and opening each tube for determining passages of the fluids, whereby a series of fluid passage switching actions can be carried out easily.
With such a fluid passage switching apparatus in a CAPD
(continuous ambulatory peritoneal dialysis) system, a series of fluid passage switching actions can easily be carried out without producing leakage of the fluid and suffering from microbism.
The present invention also provides such a fluid passage switching apparatus having an improved fitting structure of the housing, where the housing is assembled at high accuracy to have precise dimensions but with much ease and can hardly be disassembled pieces after assembled hence giving a good enough level of safety.
An aspect of the present invention provides a tube capable of minimizing the overall dimensions of the fluid passage switching apparatuses of the first and second objects.
The fluid passage switching apparatus of the present invention is improved in installing a plurality of clamps which are commonly used, are small in size, and assembled without much difficulty for clamping the tubes, thus avoiding any assembling fault such as absence of any clamp.
3a Brief Description of the Drawings Fig. 1 is a schematic view showing a back-free, twin-bag system in a conventional CAPD method;
Figs. 2 and 3 illustrate an embodiment of a fluid passage switching apparatus according to the present invention;
Fig. 4 is a schematic view showing a back-free, twin-bag system in a CAPD method employing the fluid passage switching apparatus of the present invention;
Fig. 5 illustrates a notched structure of a cam used in the fluid passage switching apparatus of the present invention; _ .
Fig. 6 is a diagram of a first positioning action of clamps selectively carried out in the fluid passage switching apparatus of the present invention for closing and opening, showing an initial state at (I), a discharge preparation state at (2), and a discharge state at (3); ., Fig. 7 is' a diagram of another positioning action of the clamps selectively carried out in the fluid passage switching apparatus of the present invention for closing and opening, showing a flushing preparation state at (4); a flushing state at ~(5), and a charge preparation state at (6);
Fig. 8 is a diagram of a further positioning action of the clamps selectively carried out in the fluid passage switching apparatus of the present invention for closing and opening, showing a charge state at (7), and an end-of action state at ($);
Fig. 9 is a diagram of the first positioning action with a tube K1 controlled fox closing and opening by a patient while other tubes K2 and K3 r 3b controlled with a plane cam, showing the initial state at 1~, the discharge preparation state at 0, and the discharge state at ~;
Fig. 10 is a diagram of the another positioning action with the tube Kl controlled for closing and opening by a patient while the other tubes K2 and controlled with the plane cam, showing the flushing preparation state at ~, the flushing state at 5~, and the charge preparation state at ~;
Fig. 11 is a diagram of the further positioning action with the tube K1 controlled for closing and opening by a patient while the other tubes K2 and controlled with the plane cam, showing the charge state at ~, and the end-of action state at ~;
Fig. 12 is a view of shells to be assembled to a fitting structure of a housing, showing an upper shell provided with a notch at (a) and a lower shell having a rib and a latch at (b); and Fig. 13 is a view of the shells shown in Fig. 12 assembled together, showing the fitting structure.
Embodiments of the Invention Fig. 2 illustrates a fluid passage switching apparatus comprising a shaft F provided with an operating handle A for pivotably holding a cam C, an upper housing shell D of a cylindrical shape having a through hole G for the shaft F and a tube accepting aperture H provided therein and arranged to fit with a lower housing shell E to form a housing for accommodating the cam, the lower housing shell E of a cylindrical shape having a tube accepting aperture I
therein at a location which is opposite to the tube accepting aperture H of the upper housing shell D, and the cam C accommodated in the housing consisting of the upper housing shell D and the lower housing shell E and arranged to be rotated by the movement of the handle A to its selected positions for opening and closing a tube B.
Fig. 3 shows another fluid passage switching apparatus having a cam C
and an operating handle J which is formed integral with a shaft joined rotatably to the cam C held to a housing L.
Also, the present invention includes a further fluid passage switching apparatus having a member provided in a housing thereof for transmitting a force to a tube of a cam to shut up the tube. The member for transmitting a force to the tube to shut up the tube may be a clamp which is movable in response to a rotating movement of the cam for closing and opening the tube.
With such a fluid passage switching apparatus mounted to a Y-shaped tube joint, e.g., of a CAPD (continuous ambulatory peritoneal dialysis) system, the switching is made at particular positions listed in Table 2. The opening and closing actions of the clamp when the positions listed in Table 2 are selected in the flow passage switching apparatus of the present invention are illustrated in Figs. 6 to 8. As shown in Figs. 6 to 8, the tubes are open when notches of the cam come across and otherwise, they are closed. The notches are provided at intervals of 90 degrees and when moved to 45 degrees, come to their next positions.
Table 2:
X position 1 K1 K2 K3 I
(initial state) open open open position 2 (prepareKl K2 K3 for dischar e) closed closed closed position 3 Kl K2 K3 (dischar e) open closed open position 4 (prepareKl K2 K3 for flushin ) closed closed closed position 5 Kl K2 K3 (flushin ) closed o en o en position 6 (prepareKl K2 K3 ~ closed ~ closed for char e) closed position 7 Kl K2 K3 (char e) o en open closed position 8 Kl K2 K3 (end of action) closed closed closed necessary positions, X : position required for the production, ~: preferably adopted position, O: preferably adopted positions in the prior art but unnecessary positions in the present invention.
The positions listed in Table 2 will now be explained in more detail.
At the initial state, the clamps Kl, K2, and K3 in the fluid passage switching apparatus when released from its package remain opened for preventing blocking up of the tubes during sterilization.
The selection from the positions listed in Table 2 may be made by manually turning the shaft or by full- or semi-automatic control of a relevant mechanism where the positions 4 to 6 are automatically controlled by time setting while the positions 1 to 3 and 6 to 8 are manually determined depending on the personal conditions of a patient such as discharge speed.
In the prior art, it is necessary to execute simultaneous actions of opening and closing the clamps Kl, K2, and K3 for determining their positions listed in both Tables 1 and 2. The present invention permits the cam to systematically control a desired group of the clamps without manually operating all the clamps. For example, in the apparatus with the cam controlling all the clamps Kl, K2, and K3, the position can be selected by using the handle while no action of manually opening and closing the clamps Kl, K2, and K3 is needed.
Accordingly, the switching of the fluid passage can easily be carried out by a patient. Also, as the fluid passage is switched by the cam or clamps pressing down and releasing the tubes, leakage of the fluid or entry of undesired bacteria can be avoided.
The present invention is not limited to the apparatus with the cam controlling all the clamps Kl, K2, and K3 and another type shown in Figs. 9 to 11 may be implemented with a cam controlling the clamps K2 and K3 while the clamp K1 is operated by a patient.
Illustrated in Figs. 9 to 10 are the action of the plane cam in response to the movement of a shaft for closing and opening the tubes at its positions.
Denoted by ~ is the initial position, 2Ois the preparatory position for discharge, ~ is the discharge position, ~ is the preparatory position for flushing, ~5 is the flushing position, ~is the preparatory position for charge, O7 is the charge position, and ~ is the end of action.
The opening and closing states of charge and discharge tubes are listed in Table 3. In Table 3, O represents the opening state of the tube and X
represents the closing state.
Table 3:
Positions ~ ~ ~ ~ ~ ~ ~
Charge tube O X X X O X O x Discharge O X O X O X X X
tube In this embodiment, the two clamps located on the same plane are controlled with a single plane cam. It is also possible to have two or more clamps arranged in parallel and controlled with the use of a corresponding number of plane cams aligned along the same shaft 90 degrees out of phase to one another.
The components of the fluid passage switching apparatus in a medical system according to the present invention will be described in more detail.
(1) Housing ~l As shown in Fig. 2, the housing comprises an upper shell D and a G
lower shell E. The upper shell D and the lower. shell E define a room in which a cam C and clamps are accommodated. The upper shell D has a handle through hole and markings of the positions for switching the flow passage provided in and on the top side thereof. The markings include the positions 3 to 8.
Tube apertures across which the tubes to be opened and closed by the cam or the clamps extend are provided in the sides of the upper and lower shells.
~2 The housing is preferably shaped to a cylindrical form and sized as small as possible.
The housing may be made of metallic material such as stainless steel etc. , ceramic, or heat-resistant synthetic resin such as polyacetal, polycarbonate, polypropylene, ABS resin, or polyethylene.
It is unnecessary to accommodate the cam in the housing. The housing is not limited to the shape and the construction so long as it can securely hold the shaft, the cam joined to the shaft, and the clamps as shown in Fig. 3.
~3 For ensuring the closing of the tube with the cam or a combination of the cam and the clamp while providing the operability of the cam with the handle, it is essential to assemble the upper shell D and the lower shell E to highly accurate dimensions. Particularly, ensuring the closing of the tube is most important and hence, the dimensional accuracy of the upper shell D and the lower shell E along the vertical direction (the thickness direction) will be crucial and towards the upward direction (a direction along which the upper shell D is separated from the lower shell E) will be more crucial. The dimensional accuracy shall be affected by any faint injury produced at the joint during the assembling of the housing by joining the two shells to each other along the vertical direction.
For eliminating the above drawback, we, the inventors, joined the upper shell D and the shell E by adhesive to each other to develop a test piece and failed to have a desired level of the dimensional accuracy A desired level of the dimensional accuracy was achieve when the two shells were assembled by thread joining which however required a considerable length of ~dorking time.
Accordingly, it was found that the thread joining was not an appropriate method in the view of practical production.
Through a series of experiments, we, the inventors, found that the upper shell D and the lower shell E were joined to each other for achieving the above task not by the thread joining but by giving a specific fitting arrangement which is described below in more detail.
The fitting arrangement is implemented by placing the upper shell D
over the lower shell E, turning it to engage its notch P with a rib Q provided on the lower shell E, and sliding and fitting a latch R of the lower shell E to a predetermined location in the notch P, as shown in Figs. 12a and 12b. In the fitting arrangement, the engagement between the notch P of the upper shell D
and the rib ~.l of the lower shell E determines the vertical position of the two shells D and E. When the latch R has been moved over a slope U provided on the upper shell D, its side r1 comes opposite to a facet p1 of the notch P in the engagement.
The use of the fitting arrangement permits the notch P and the rib Q for determining the vertical positioning of the housing to be free from physical injury during the joining, hence achieving a desired level of the dimensional accuracy on the housing. Also, the latch R of the lower shell E, the slope U
and the facet p1 at the notch P of the upper shell D may be injured due to severe friction. Such resultant injuries are too small to affect on the vertical dimensional accuracy of the housing.
The latch R makes the engagement between the upper and lower shells D
and E easy and after the engagement, acts as a stopper which prevents the separation of the two shells from each other. Accordingly, the latch R is not limited to a particular shape while providing the above mentioned function.
Preferably, the latch R has a facet r2 provided thereon for ease of the assembling the upper and lower shells. The rib Q and the latch R may be formed integral with the lower shell E or fabricated separately and then joined to the lower shell by an appropriate joining means.
The shape of the rib Q in the fitting arrangement is not of limitations while it enables to engage with the notch P for determining the vertical positioning of the upper and lower shells. Preferably for improving the strength of the apparatus, the location of the rib Q and the notch P is so determined that the edge region at the open end of the lower shell where the rib Q is provided comes into direct contact with the inner side of a circular top region of the upper shell.
The fitting arrangement is not limited to that shown in Figs. 12 and 13 and an alternative rnay be used where the notch P is provided in the lower shell E while the rib Q and the latch R are provided on the upper shell D.
Also, the fitting arrangement may include a means for determining the vertical positioning (particularly along the upward direction) so as to allow any two horizontally extending surfaces to directly fit each other. Although the downward positioning is determined by the facet q1 of the rib Q and the facet p2 at the notch P and the upward positioning is by the facet q2 and the facet p3 in the above example, they may be determined by the facet r3 of the latch R
and the facet p2 at the notch P and by the facet q2 and the facet p3 respectively so that facet r1 of the latch R and the facet p1 at the notch P come into direct contact and are engaged with each other. Furthermore, it is possible that the dimensional accuracy along the upward direction at least is maintained by the facet q2 of the rib Q and the facet p3 at the notch P with a clearance provided between the facet q1 and the facet p2 at the notch P so that the facet r1 of the latch R and the facet p1 at the notch P directly engage with each other.
Although at least a single of the fitting arrangement is sufficient to be provided in the housing, it is preferred to have two to five of the fitting arrangements to prevent leftward and rightward displacement of the upper shell D and the lower shell E during the turning movement of the shaft.
(2) Shaft The apparatus allows the patient or operator to select desired one of the positions by turning the handle joined to the shaft.
(3) Cam The cam has a construction which is rotated by the controlling action of the shaft to any desired position for opening or closing the corresponding tube directly or with the help of a clamp and may be selected from a plane cam and a solid cam.
The cam employed in the embodiment has notches provided therein as shown in Figs. 2 and 5. The structure a of the cam shown in Fig. 5 includes a portion b for maintaining the tube at its opening state, a portion c for shifting the tube from the closing state to the opening state, a portion d for maintaining the tube at its closing state, and a portion a for shifting the tube from the opening state to the closing state.
The distance between the portion b for maintaining the tube at its opening state and the portion d for maintaining the tube at its closing state is a length required for opening or closing the tube with or without the clamp. For example, in case that the tube is closed with the cam and its thickness is ignored, the distance is substantially identical to the diameter of the tube.
When the cam is involved, its shape varies the distance which shall be higher or lower than the diameter of the tube.
The portion c for shifting the tube from its closing state to the opening state is diverted an angle of 45 to 135 degrees clockwisely from the horizontal plane of the portion d and preferably, within a range from 85 to 95 degrees to prevent the reverse rotation. The angle of the portion a for shifting the tube from the opening state to the closing state is determined by the angle of the clamp. Because the strength is not required at the initial stage of closing the tube but needed at the final stage for pressing down the tube, it is preferable that the portion a consists of a steep slope III and a moderate slope II as shown in Fig. 3. The moderate slope II which transmits the pressing force of the cam continuously and lightly to the distal end IV of the clamp may preferably have a curved surface rather than a flat surface.
The cam C has a circular shape in the plan view of which the diameter is 40 to 90 percent of the diameter of the housing comprising the upper shell D
and the lower shell E and more preferably 70 to 80 percent.
The number of the notches shown in Fig. 4 and 5 is determined by the number of the positions.
When the positions are three, one notch is provided. The positions for discharge, flashing, and charge are essential as their tasks are satisfied with K2 closed, Kl closed, and K3 closed respectively. As shown in Fig. 5, one single notch d does the tasks. If four to eight of the positions are desired, the number of the notches is 3.
(4) Tube Ol The tube commonly employed in a medical fluid passage switching apparatus (e.g. for a CAPD passage) may be of 5 mm in the inner diameter and 7 mm in the outer diameter. However, when the tube of such a size is used in the medical fluid passage switching apparatus which comprises at least a rotatable shaft, a cam arranged for turning in relation to the rotating movement of the shaft to open and close the tube which provides a fluid passage, and a housing having tube holes provided therein and arranged for accommodating the cam, the overall size of the apparatus will be increased.
The reason is that the diameter and the height of the cam are determined by the outer diameter of the tube while the height of the interior space of the housing should be greater than the outer diameter of the tube. Also, as the tube is made greater in the outer diameter and the thickness, the force l0 requireel on the handle has to be increased thus disturbing the rotating operability of the handle.
~J When the tube employed in a nnedical fluid passage switching apparatus (e.g. for a CAPD passage) is decreased in the size, the drawback that the overall dimensions of the apparatus becomes large may be eliminated. On the other hand, the reduction of the tube size, particularly the inner) diameter, will decrease the flow of a fluid. For example, with a tube having 3 mm of the inner diameter instead of 5 rrim in the inner diameter and 7 mm in the outer diameter, the discharge took 5 % more in duration than with the above mentioned tube.
According to the present invention, the size, particularly the firmer diameter, of the tube shall be determined in consideration with the duration required for the discharge caused by the reduction of diameter of the tube.
The tube having a reduced diameter may be 1 to 4 rr>ln in the inner diameter and 2 to 5 mm in the outer diameter. It is more preferable that the inner diameter is 3.5 mm, the outer diameter is 4.5 mm, and the thickness is 0.5 mrn.
The diameter reduction of the tube may be implemented at each particular portion on which the clamp or a combination of the clamp and the cam presses down to open and close the tube., Alternatively, the entire body (of a three-directional shape) of the tlxbe in the apparatus may be reduced in the diameter.
The three-directional tube may be arranged so that gradually increasing its diauneter 1T'Om their opeming/closing portion towards the open end of each directional tube.
For example, the open end of each branch of the three-directional tube is sized to 2 ix~ 9 mm in the inner diameter and ~l to 10 nm in. the outer diaxmeter for ease of joining with conventional tubes.
'rhe i;hree-directional tube may be fabricated by bonding the portions of reduced diameter with other portions by adhesive or be unified by injection molding.
Also, the portions other than the portions of reduced diameter may preferably be fabricated by rW g-life members which can sandwich holes H of the upper shell D
and holes.I of lower shell E fram both outer and inner sides of housing or a member having ring-like region to be provided on the outer side of holes I-i of the upper shc, )l D. The ring-like members or regions permit; the three-directional tube to be easily secured to t;he housing. The ring-like regions may be shaped by integral rnoldini; or the ring-like members may be joined to the tube by appropriate joining means.
The thickness of the tube is a critical factor for determining the strength required for ensuring the air-tightness in the tube. The smaller the thickness, the less the strength is required for ensuring the air-tightness in the tube thus improving the rotational operability of the shaft. The thickness may be 0.1 to 1.5 mm and more preferably, 0.3 to 0.7 mm.
When the thickness of the tube to be closed and opened is as small as 0.3 to 0.7 mm, the apparatus will be of a (direct) type where the tube can directly be closed with the cam.
~3 It was found through , studying the reduction of the number of components and the dimensions of the medical fluid passage switching apparatus and the decrease of the height of the apparatus that while a commonly adapted tube having 5 mm of an inner diameter and 7 mm of an outer diameter suffered from damage when pressed down directly with the cam for closing and opening, the tube having a thickness of 0.3 to 0.7 mm was successfully pressed down for closing and opening by the cam without being damaged.
It is presumed that the reduction of the thickness of the tube minimizes the strength required for actuating the cam to close the tube.
In such a direct type of the apparatus, the clamp can be omitted and thus the thickness of the cam can be decreased . Accordingly, in addition with the effect of the tube having a reduced thickness of tube wall and reduced inner diameter, the medical fluid passage switching apparatus can be minimized in the number of its components, reduced in the height, and designed to a compact structure. Also, as the direct type of the apparatus is shortened along the radial direction as well as in the thickness direction, its overall dimensions can further be reduced.
(5) Clamp The clamp is preferably fabricated comprising a pair of projections for closing and opening the tube in relation with the movement of the cam and an arcuate member joining the two projections. Whenthe clamp has moved from the portion d via the portion c to the portion b at the notch of the cam, the tube is released. Since its arcuate member has a self returning-back function, the clamp will hardly prevent the recovering action by the resiliency of tube thus ensuring quick opening of the tube. However, the clamp in the present invention is not limited to a structure described above and other structures will be used including one having the two projections joined by a hinge to each other at corresponding recessed region and another having a pair of sheet-like members slidably supported on a bridge member.
In case that the medical fluid passage switching apparatus of the present invention includes a plurality of the clamps, the clamps may be provided in a single unit or each clamp may be formed integral with another component.
For example, the upper parts (which are closer to the cam than to the tube) of the clamps are formed as a single unit while the lower parts (which are closer to the tube than to the cam) of the clamps are formed as a single unit. This will eliminate the difficulty of the clamps being installed during the assembling of the medical fluid passage switching apparatus or avoid such an assembling fault as absence of any clamp.
The lower parts of the clamps may be formed integral with the inner wall of the lower shell E of the~housing. Since the clamps are formed as units, the number of components in the apparatus will be minimized and the overall height of the apparatus will be reduced.
When the medical fluid passage switching apparatus of the present invention is of the direct type, the lower parts (which are closer to the tube than to the cam) of the clamps may also be formed as a single unit. Similar to the above case, the upper parts may be formed integral with the inner wall of the lower shell E of the housing.
The cam in said direct type apparatus may preferably be reduced in the thickness of the portion of the wall to close the tube in comparison with the cam used in the apparatus type using the clamps. The configuration of the portion having the role to close the tube in the cam is preferably formed curved shape. Furthermore, it is favorable to form projections in lower parts of cam to fit into the recess formed in lower parts of clamps.
With the use of the medical fluid passage switching apparatus and the tube according to the present invention, the fluid passage switching action by a patient will be carried out with ease. Also, the passage is switched by the cam or the clamps pressing down and releasing the tubes and hence leakage of the fluid or entry of undesired bacteria will be avoided.
The medical fluid passage switching apparatus of the present invention is effectively used as a Y-shaped tube joint form of a fluid passage switching apparatus in a CAPD (continuous ambulatory peritoneal dialysis) system.
Also, the same apparatus may replace a conventional fluid passage switching apparatus in a fluid passage system which is commonly employed in the form of a three-directional valve.
When the medical fluid passage switching apparatus of the present invention is used in such a known system, various problems with the three-directional valve including leakage of a fluid and entry of unwanted bacteria will be eliminated. Such a known system may be an infusion system. Also, the apparatus is applicable in a system for doping a mixture of different medical liquids provided by single fluid preparation (simultaneous mixing) (e.g.
a mixture of glucose and a liquid containing amino acid and electrolysis for nutrition infusion and a mixture of a carbonic acid contained liquid and a glucose contained liquid for bicarbonate contained peritoneal dialysis), a blood circuit, a transfusion system, or a blood components separating system.
In case that the medical fluid passage switching apparatus of the present invention includes a plurality of the clamps, the clamps may be provided in a single unit or each clamp may be formed integral with another component.
For example, the upper parts (which are closer to the cam than to the tube) of the clamps are formed as a single unit while the lower parts (which are closer to the tube than to the cam) of the clamps are formed as a single unit. This will eliminate the difficulty of the clamps being installed during the assembling of the medical fluid passage switching apparatus or avoid such an assembling fault as absence of any clamp.
The lower parts of the clamps may be formed integral with the inner wall of the lower shell E of the~housing. Since the clamps are formed as units, the number of components in the apparatus will be minimized and the overall height of the apparatus will be reduced.
When the medical fluid passage switching apparatus of the present invention is of the direct type, the lower parts (which are closer to the tube than to the cam) of the clamps may also be formed as a single unit. Similar to the above case, the upper parts may be formed integral with the inner wall of the lower shell E of the housing.
The cam in said direct type apparatus may preferably be reduced in the thickness of the portion of the wall to close the tube in comparison with the cam used in the apparatus type using the clamps. The configuration of the portion having the role to close the tube in the cam is preferably formed curved shape. Furthermore, it is favorable to form projections in lower parts of cam to fit into the recess formed in lower parts of clamps.
With the use of the medical fluid passage switching apparatus and the tube according to the present invention, the fluid passage switching action by a patient will be carried out with ease. Also, the passage is switched by the cam or the clamps pressing down and releasing the tubes and hence leakage of the fluid or entry of undesired bacteria will be avoided.
The medical fluid passage switching apparatus of the present invention is effectively used as a Y-shaped tube joint form of a fluid passage switching apparatus in a CAPD (continuous ambulatory peritoneal dialysis) system.
Also, the same apparatus may replace a conventional fluid passage switching apparatus in a fluid passage system which is commonly employed in the form of a three-directional valve.
When the medical fluid passage switching apparatus of the present invention is used in such a known system, various problems with the three-directional valve including leakage of a fluid and entry of unwanted bacteria will be eliminated. Such a known system may be an infusion system. Also, the apparatus is applicable in a system for doping a mixture of different medical liquids provided by single fluid preparation (simultaneous mixing) (e.g.
a mixture of glucose and a liquid containing amino acid and electrolysis for nutrition infusion and a mixture of a carbonic acid contained liquid and a glucose contained liquid for bicarbonate contained peritoneal dialysis), a blood circuit, a transfusion system, or a blood components separating system.
Claims (9)
1. A tube for use in a medical fluid passage switching apparatus for carrying out a series of fluid passage switching actions of a plurality of tubes connected to each other at one end, wherein, at a region where a cam of the apparatus or a combination of the cam and a clamp of the apparatus is engaged with the tube for closing and opening the tube as compared with a region where the tube is not so engaged, the tube is decreased in diameter, is thinned in a wall or is decreased in diameter and thinned in a wall.
2. A tube for use in a medical fluid passage switching apparatus for carrying out a series of fluid passage switching actions of a plurality of tubes connected to each other at one end, wherein the tube is decreased in diameter at a region where a cam of the apparatus or a combination of the cam and a clamp of the apparatus is engaged with the tube for closing and opening the tube as compared with a region where the tube is not so engaged.
3. A tube for use in a medical fluid passage switching apparatus for carrying out a series of fluid passage switching actions of a plurality of tubes connected to each other at one end, wherein the tube is thinned in a wall at a region where a cam of the apparatus or a combination of the cam and a clamp of the apparatus is engaged with the tube for closing and opening the tube as compared with a region where the tube is not so engaged.
4. A tube for use in a medical fluid passage switching apparatus for carrying out a series of fluid passage switching actions of a plurality of tubes connected to each other at one end, wherein the tube is decreased in diameter and thinned in a wall at a region where a cam of the apparatus or a combination of the cam and a clamp of the apparatus is engaged with the tube for closing and opening the tube as compared with a region where the tube is not so engaged.
5. The tube according to any one of claims 1 to 4, which has a three-directional branched configuration.
6. The tube according to any one of claims 1 to 5, which has an inner diameter of 1 to 4mm and an outer diameter of 2 to 5mm.
7. The tube according to any one of claims 1 to 6, which has a thickness of 0.3 to 0.7mm.
8. The tube according to claim 4, wherein an inner diameter and an outer diameter gradually increase from the region where the cam or the combination of the cam and the clamp is engaged with the tube for closing and opening the tube, towards an open end of the tube.
9. The tube according to claim 8, wherein the inner diameter is 2 to 9mm and the outer diameter is 4 to l0mm near the open end of the tube.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10/249,226 | 1998-08-19 | ||
| JP24922698A JP3965796B2 (en) | 1997-08-19 | 1998-08-19 | Medical fluid flow switching device |
| CA 2341194 CA2341194C (en) | 1998-08-19 | 1998-10-09 | Medical fluid passage switching apparatus |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2341194 Division CA2341194C (en) | 1998-08-19 | 1998-10-09 | Medical fluid passage switching apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2544439A1 true CA2544439A1 (en) | 2000-03-02 |
Family
ID=36693878
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002544439A Abandoned CA2544439A1 (en) | 1998-08-19 | 1998-10-09 | Tube for medical fluid passage switching apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2544439A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2022531A1 (en) * | 2007-07-31 | 2009-02-11 | Covidien AG | Liquid coinjector |
| EP2042214A1 (en) * | 2007-09-27 | 2009-04-01 | Covidien AG | Liquid coinfusion device |
-
1998
- 1998-10-09 CA CA002544439A patent/CA2544439A1/en not_active Abandoned
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2022531A1 (en) * | 2007-07-31 | 2009-02-11 | Covidien AG | Liquid coinjector |
| EP2042214A1 (en) * | 2007-09-27 | 2009-04-01 | Covidien AG | Liquid coinfusion device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Dead |